Handpiece for dental engines



C. B. BISHOP.

HANDPIECE FOR DENTAL ENGINES.

APPLICATION FILED APR. 4,1916.

Patented June 14, 1921.

Emmntm:

UNITED STATES PATENT OFFICE.

CHARLES B. BISHOP, OF NEW YORK, N. Y., ASSIGNOR TO CONSOLIDATED DENTAL MANUFACTURING COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

-HA NDPIEGE FOR DENTAL ENGINES.

Specification of Letters Patent. Patented J 11116 145,

Application filed April 4, 1916'. Serial No. 88,838.

, To all whom it may concern;

Be it known that I, CHARLES B. BISHOP, a citizen of the United States, and resident of the borough ofManhattan, in the city and State of New York, have invented a new and useful lmprovement in Handpieces for Dental Engines, of which the following is a specification.

My invention relates to an improvement in handpie'ces for dental engines, and particularly handpieces used in that class known as all cord dental engines, with the object in view of providing certain arrangements whereby a convenient and positive mechanism is provided for properly-adjusting the drill spindle in its bearings and for maintaini'ng such adj u'st'ment.

Another object is to provide a case for the handpiece which is of two-part construction, and hence strong, light and sanitary; and which case has, as an integral part thereof, a stud for the temporary attachment of the cross head. r

A further object is to provide certain improvements in the form, construction and arrangement of the several parts whereby the above mentioned and other objects may I be effectively carried out.

A practical embodiment of my invention is represented in the accompanying drawings, in which Figure" 1 represents a' side elevation of the assembled handpiece with the cross head secured thereto,

Fig. 2 represents a vertical section taken in the plane of the line A--A of Fig. 1, looking in the direction of the arrows,

Fig. ,3 represents a transverse section taken inthe plane of the line B-B of Fig. 1, looking in the direction of the arrows, and

Fig. 4 represents atransverse detail section taken in the plane of the line C-C of Fig.'1, looking in the direction of the arrows.

The devicehas the customary-head piece or frame 1, with its projecting sleeve 1*, which head piece serves to carry the hand piece as a whole; the drill spindle 2 with its clutch mechanism 3, clutch operating rod 4, milled thumb wheel 5, and driving pulley 6'; the said pulley being fixed against rotation on the spindle 2 by a set screw 7.

The particular construction and arrangement of these elements constitutes no partof my invention, and, as they are of well known and approved form, they will not be further described. I The body of the case is denoted by 8, and 1t consists of a single, tubular piece, which may conveniently be formed of machined steel, suitably roughened on the exterior as at 9, to providea suflicient hand gripfor theoperator. By making this of a single piece, I have departed from the former well established practice which was to constitute this part of the case by telescopically associating a plurality of sections (generally three), the engaging extremities of which were complementarily tapered and flared,-

tom, in view of the fact that the points of union of the several sections were somewhat unsightly, to provide an exterior sleeve of some material, such as hard rubber or fiber; the said sleeve serving to conceal said joints and, at the same time, act as a hand-grip for the user. This former arrangement had a distinctly objectionable feature 'on the 7 ground that it was less sanitary than was to be desired. It willbe clear that the form of case which I have devised. is not only provided with a surface which serves as a. hand grip, but, byits integrality of the body portion eliminates the requirement of any exterior covering. q I

The tool holding end of the-hand piece has the customary tapered nose 10, which is secured in the end of theca'se 8 by soldering or in any other convenient manner and serves as a bearing for the front end of the spindle; while the rear end of the latter is reduced in diameter and mounted in a cylins drical bearing 11, which isthreaded into the head piece 1, as clearly shown in Fig. 2. The inner end of the bearing 11 is flared so as to have a smooth surface engagement with the shoulder formed on the spindle 2 r V a whole, thereby providing means for ading,together with'a set'screw for the purpose of securing the bearing inthe desired serving to lock the case to the said head piece. 7 p

Reverting to the bearing 11, 1t w1ll be observed that its threaded engagement with i r the head piece '1 renders it longitudinally adjustable with respect to the hand piece as justing the fit of the spindle 2 in its bearings 10 and 11. For the purpose of operating the bearing 11, a toothed or notched. wheel 15 is 'provided'at one end thereof, which may be reached by the operators fingers. After the bearing 11 had been adjusted, it is locked against movement by means of a clip 16 c which is secured to the head 1 by a screw 17 and has a lug 18 fitted to engage the interstices between the teeth on the wheel 15.

The notches on the periphery of the wheel 15 amount, in effect, to calibrations.

The lug may be disengaged from the teeth of the wheel 15 by loosening the screw 17 and slightlyraising the clip 16.

With regard to this adjustment and its locking arrangement, itmay be said that it has formerly: been customary to merely providea device for turning the-rear end bear- **adjustment.' However, the point of engage 'ment' between the locking set screwand the 1 l the lug 18 and the wheel 15, is visible and bearing has been invisible, so that the operator'was not sure whether he had really effectually locked the bearing in its adjustment ornot; and again, the operator would frequently neglect to turn down the set screw, 45

' "ence in its appearancewhetherit was tight owing to the fact that there was no differor loose. Consequently, it was a fact of frequent occurrence that the spindle hearing would, in the course of operationpalter its position'jthus failing to constitute a proper bearingsurface for the spindle,,with the result of undue noise in operation and wear on the parts. v 5 I H V my improved arrangement, on the other hand, the locking engagement between positive, so that thereis no chance of' a failure to lock the bearing aga nst movement and practically no chance of the operator vforgetting to engage the locking means. f

- A conventional f'fo'rm of right ';angle at-f tachment is denoted by 19, which is provided with an open end 20, for engaging :the hand" piece in the customary manner. As a means of" locking thls attachment against rotation on the hand piece, a stud 21 is provided, whichstud is integral with the body portion 8 of the case, and formed by striking outwardly a portion thereof. This stud is adapted to fit in a slot 22 in the hollow end 20 of'the attachment19, in the usual manner. Formerly, this stud was generally formed by threading a little screwinto the proper part of the case 8. By my improvement, the end of cheapness andsimplicity of manufacture is not only obtained but the danger of the stud falling out is, of course, absolutely prevented. Moreover, inasmuch as the screw formerly usedpiercfed the easing, the lubricating oil frequently leaked out and oiled the fingers of the operator a very disadvantageous feature, which-is fully overcome by my said improvement.

The operation of the device will be apparent from the foregoing description, and I desire it to be understood that various changes may be resorted to in the form, construction and arrangement :of the several and an exteriorlv screw threaded portion, a

hand niece comprising case: mounted on said sleeveand provided at one endwith an annular flange arranged to abut said threaded portion, and a hollow nut adapted to enave said'flange and' threaded portion for lock ng the case to the head niece and sleeve;

ln'comhination'with the head. piece of a dental enmne' having a proiecting sleeve and exteriorlv screw threaded portion, a hand niece comprising a unitary tubular case mounted on said sleeve and provided at one end with an annular'fiange arranged to abut s id threaded portion, and a hollow nut adapted to engage said flange'and threaded portion for locking the case'to' the head piece andsleeve, f

3. In combination with the head piece of a dental engine having ac'ase removably secured thereto, a spindle rotatably housed in said case, bearings in the case arranged to support said spindle, one of said'bearings having a screw threaded engagement with the head piece, a calibrated wheel carried bv said bearing, and a clip removably secured on the head piece and provided with a V shaped lug overhanging said calibrated sur face in position to enter one of the calibrations to lock the wheeland bearing in'a predetermined position.

4. In combination with the head piece of a 7 dental engine having a case removably secured thereto. a spindle rotatably housed in said case, a fixed bearing located atthe outer end of the case, a bearing having a screw brated surface in position to enter one of the threaded engagement with the head piece calibrations to lock the wheel and bearing and longitudinally movable in the inner end in a predetermined position. 10 of the case, a calibrated wheel carried by In testimony, that I claim the foregoing as said bearing, and a clip removably secured my invention I have signed my name this on the head piece, a V shaped lug depending 31st day of March, 1916.

from said clip and overhanging said cali- CHARLES B. BISHOP. 

